1. Field of the Invention
The invention generally relates to roofing tiles and more particularly to a system including a plurality of partially overlapping rows of roofing tiles in side-by-side relation on a pitched roof, with neighboring roofing tiles in adjacent rows interlocked.
2. Description of the Prior Art
A building roof typically includes a layer of rigid material attached to joists or beams to form planar substrates. The roof is made weather tight by the application, on the substrates, of weather proof material having provisions for positive drainage. A typical arrangement is a pitched roof consisting of one or more sections of planar substrates, pitched at an angle to promote downward run-off from an uppermost edge toward a lowermost edge. Uppermost edges of adjacent sections may meet at a peak defined by the boundary between the sections. Each roof section is typically covered by weather proof tiles attached in overlapping rows of tiles in side-by-side relation. Each row of tiles overlaps neighboring tiles in the next lower row. Gaps between adjacent side edges of tiles forming a row are usually partially covered by an intermediate portion of a tile in the next row upward. The peak is covered by curved tiles having opposed lower side edges and a higher central ridge, which curved tiles direct draining water downward onto each of the adjacent roof sections.
Roofing tiles may be formed of rigid or flexible material but in either case, it is common practice to attach the tiles by driving a fastener, such as a roofing nail, through the tile, at a location proximate to the uppermost end, and into the substrate. A first row of tiles is attached at the lowermost edge of a roof section, in side-by side relation. A next row of tiles is attached in the same manner partially overlapping the first row and protecting the uppermost end by covering the holes through which the fasteners pass into the substrate. It is necessary to cover the holes so that water leaks will be avoided, when water drains downward across the roofing tiles. The area of each of the roofing tiles proximate to the lower end, is exposed, while the area proximate to the upper end, including the holes, is protected by the next upper row of tiles. The exposed ends of the tiles are not known to be attached by a fastener.
A moderate wind may cause movement of the exposed ends of flexible roofing tiles. The movement is characterized by flexing of the tiles. The flexing movement absorbs the force exerted by the wind and the protected ends of the tiles may or may not transmit appreciable force to the roofing nails holding the tiles in place. Flexible tiles are known to tear from the secured section or break free in sheets when exposed to a strong enough wind. Rigid roofing tiles are typically heavier than flexible tiles and remain stationary in moderate winds. The rigid roofing systems are generally substantially more costly than flexible roofing systems and are expected to have a significantly longer useful life.
In high winds, the exposed ends of rigid roofing tiles are also moved. The tiles do not flex and the movement is transmitted to the area proximate to the protected ends and force is applied to the roofing nails. The nails may become dislodged causing tiles to slide or become free from their position exposing the roof to possible leaks and tile breakage. There is a need for a system, which provides for areas of the tiles proximate to the exposed ends to be attached, thus preventing movement. There is a need for a system including means for interlocking adjacent rows of tiles for a more secure roof.